Enzyme-catalyzed method for preparing vitamin A palmitate

Abstract

The invention provides a method for preparing vitamin A palmitate by enzyme catalysis, and relates to a synthesis method of vitamin A palmitate. The method comprises the following steps of (1) dissolving the vitamin A palmitate and low-grade fatty alcohol palmitate into an organic solvent, and adding lipase; (2) performing vacuum pumping from a condenser, performing enzyme catalysis ester exchange reaction, and separating out a reaction byproduct of low-grade fatty alcohol acetate and an organic solvent through a rectifying column; (3) removing lipase from reaction material liquid, adding an adsorbent for adsorbing remained low-grade fatty alcohol palmitate, and filtering out the vitamin A palmitate solution; and (4) performing organic solvent reduced pressure evaporation to obtain the vitamin A palmitate. The oxidation cannot easily occur; meanwhile, the enzyme catalysis ester exchange is used during the reaction; the reaction conditions are mild; the side reactions can be effectively inhibited; the operation is simple; the reaction yield is high; and the product quality is high.

Description

technical field [0001] The invention relates to a synthesis method of vitamin A palmitate, in particular to an enzyme-catalyzed method for preparing vitamin A palmitate. Background technique [0002] Vitamin A palmitate is a known compound whose structural formula is as follows: [0003] [0004] Vitamin A palmitate has been widely used as medicine, food additive and feed additive etc. Various synthetic methods have been reported. [0005] The applicant disclosed a synthesis method of vitamin A palmitate in Chinese patent CN102363606B, using vitamin A alcohol and halogenated amide dissolved in an organic solvent, then adding a phosphorus compound for halogen replacement reaction, and filtering to remove by-products generated during the reaction process , the filtrate is cooled to crystallization to obtain a vitamin A halogenated product; the vitamin A halogenated product and palmitate are dissolved in an organic solvent, and after adding an organic base to react, severa...

AI Technical Summary

Problems solved by technology

[0007] 1. Vitamin A acetate uses immobilized enzymes to catalyze the synthesis of vitamin A palmitate in two steps, and it is filtered many times, and the steps are cumbersome;

[0008] 2. Vitamin A acetate reacts with lower alcohols, and the immobilized esterase is filtered out. The filtrate needs to be decompressed to evaporate excess lower alcohols to obtain vitamin A alcohol. Because vitamin A alcohol is unstable, vitamin A alcohol is easy to deteriorate when heated during the process, thus affecting Product quality and appearance;

[0009] 3. Vitamin A acetate reacts with lower alcohols, and the immobilized esterase is filtered out. The excess lower alcohols are evaporated from the filtrate under reduced pressure to obtain vitamin A alcohols. The concentration of lower alcohols is difficult to control, so that the lower alcohols in vitamin A alcohols remain. Subsequent reaction with palmitic acid produces by-products, which affect the quality of vitamin A palmitate

[0011] 1. The use of high-grade fatty acid anhydrides has a high cost;

[0012] 2. The use of vitamin A alcohol has poor stability, and vitamin A alcohol is easy to deteriorate, thereby affecting product quality and appearance, and increasing post-processing costs

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